Reference 3634, known as the Zenith Defy World Timer, is a 1970s automatic in stainless steel that adds a reading of the world’s time zones to the local time. It is a model appreciated by enthusiasts of vintage Zenith, especially when preserved with its original bracelet.
The model
Its defining element is the blue bidirectional rotating bezel, graduated with world times: by turning it and aligning the local time with the reference city, one obtains an approximate reading of the time in other zones, on the principle of many vintage world timers. The blue dial carries tritium indices and hands, aged to an even patina; the date sits between 4 and 5 o’clock. The crown bears the Zenith star. The 38 mm stainless steel case was declared water-resistant to 50 metres; the stainless steel bracelet is by Gay Frères, a maker highly regarded by collectors.
The movement
The movement is the automatic Zenith calibre 2552 PC, with central seconds and date, considered reliable and precise for its time.
Technical details
| Brand | Zenith |
|---|---|
| Model | Defy World Timer |
| Reference | 3634 |
| Movement | Automatic, Zenith calibre 2552 PC |
| Case | Stainless steel |
| Dimensions | 38 mm |
| Period | 1970s |
| Functions | Hours, minutes, seconds, date, rotating bezel with time zones (GMT) |
| Crystal | Mineral |
| Bracelet | Stainless steel bracelet |
